Sony 16-50 2.8 vs Sigma 17-70 "C"

I'm looking to upgrade from the kit lens on the a57 and am considering Sony's 16-50mm and Sigma's 17-70 "C" lens. Any thoughts on the two? I looked at a couple reviews online and it seems like they are both similarly sharp when comparing them at the same focal length and aperture, but the Sigma looks a little sharper wide open (which, of course, is slower than the Sony at the longer end). Both have the SSM/HSM focusing mechanism. Given all this, it seems like my decision really boils down to whether I want the faster apertures on the long end of the lens in the Sony or the greater reach of the Sigma. (I know the Sony is also weather sealed, which might be nice to have at some point but my a57 is not and I don't plan on upgrading cameras any time soon.)

I've also looked at the Sigma 17-50 2.8 a little bit. It too has the HSM motor and seems slightly sharper than the Sony 16-50 at 2.8, but the Sony seems to have it beat once stopped down.

Perhaps consider what focal lengths you are likely to use most and how important extended warranty (Sigma warranties are now usually 3 years, Sony still 1 year) and weather sealing are to you (only in the Sony).

My copy of the Sony 16-50 is very sharp from 20mm-50mm, and has nice contrast and colors, but is really quite soft at 16-18mm unless I stop down to about f8 and sharpen quite aggressively. Even then, the corners can be a mess. My Sigma 10-20 smokes the Sony in terms of sharpness at the wide end. I still like the lens as a walkaround - you just have to try to remember to stop it down when shooting subjects like landscapes or architecture at the wide end. Some also complain about the complex distortion at the wide end, but to be honest I find DXO Optics Pro does a decent job of dealing with that (I shoot raw). The build and focus are very nice - there are a few reports of SSM failures on some 16-50s, but not many. maybe also consider the Tamron 17-50 2.8 too? I found that better at the wide end than the Sony, but of course it's not SSM/HSM and isn't quite as wide...

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"When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence." Ansell Adams.

I'm looking to upgrade from the kit lens on the a57 and am considering Sony's 16-50mm and Sigma's 17-70 "C" lens. Any thoughts on the two? I looked at a couple reviews online and it seems like they are both similarly sharp when comparing them at the same focal length and aperture, but the Sigma looks a little sharper wide open (which, of course, is slower than the Sony at the longer end). Both have the SSM/HSM focusing mechanism. Given all this, it seems like my decision really boils down to whether I want the faster apertures on the long end of the lens in the Sony or the greater reach of the Sigma. (I know the Sony is also weather sealed, which might be nice to have at some point but my a57 is not and I don't plan on upgrading cameras any time soon.)

I've also looked at the Sigma 17-50 2.8 a little bit. It too has the HSM motor and seems slightly sharper than the Sony 16-50 at 2.8, but the Sony seems to have it beat once stopped down.

Any advice anyone has would be much appreciated.

I have the new Sigma 17-70 "C" Its a great lens, especially for the cost.

I have also been researching the Sony 16-50 2.8 to see if it is an upgrade worth the money

Sigma:

Pros

Flat sharpness center to edge at all by wide angle

Sharpest at F5.6

70mm extra reach and long-end

Lower CA than Sony

Pretty Silent Focus (in quite locations automatic gain on they A77 mic pics up some clicking as it starts, stops or changes direction)

Price under $500

Looks really nice with monochrome design and is compact

Cons

F4 at 70 mm where it is a good portrait lens length BUT may not have narrow enough DOF for some types of portraits

Sharpest at F5.6

Drops out of F2.8 soon and is one stop slower by 70mm

Lens switch has to be changed for MF, no DMF no full time manual override adjustments like Screwmount with DMF or SSM

No weather sealing

Sony Lens JPG compensation does not support lens

Sony

Pros

Very sharp at F4 at all FL and pretty flat response (sharper than Sigma)

extra reach and wide end

F 2.8 available at all FL one stop more light at 50mm

Less distortion at long end 50mm than sigma

Super Silent Focusing

Manual Focus Ring usable at all times for fine tuning

Weather Sealed like A77 body

Sony internal lens jpg compensation function supports lens

Cons

Can be soft and edge soft at F2.8 at all FL (but Sig doesn't even have option)

Sony bodies don't simulate DMF feature of turning on focus peaking like screw mount, should be simulated in AFS (Push since neither lens support 100% of DMF function)

More CA than Sony

Larger than Sigma

I used SLR GEAR tests to evaluate the lenses.. and my personal use of Sigma to confirm it is a nice lens.

For me optically they are close and I am not sure Sony is worth more. SSM and weather sealing have me thinking about it. If Sony simulated full DMF by turning on focus peaking after an AFS event.. so it behaved like a screw mount lens on DMF ... I would buy it for sure. Right now.. I am sticking with the Sigma because I own it and it would cost me about $250 to upgrade.

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K.E.H. >> Shooting between raindrops in WA<<Don't Panic!.. these are just opinions... go take some pictures..

I went with the Sony 2+ years ago. And it is the only zoom lens I care about. It has been on the a55 practically all the time. I find the lens quite sharp wide open at any aperture. At f/4, I would say it is as sharp as a zoom lens gets.

SSM is super quiet, close focus (and 1:4 magnification), no zoom creep (my only Sigma HSM is 18-250 which loves to zoom on its own), no CA issues. I also love the contrast and color out of the Sony (Sigma lenses seem to favor green a bit). The only advantage to Sigma might be that it gives you about 20mm more reach... nice to have but I would rather gain at the wider side. And price.

Needless to say, DT 16-50/2.8 SSM on a55 and E 35/1.8 OSS on NEX-6 are my go to options. For extra reach, I generally have Sigma 70/2.8 and usually Sony 135/2.8 STF at hand anyway to go on either camera.

I went with the Sony 2+ years ago. And it is the only zoom lens I care about. It has been on the a55 practically all the time. I find the lens quite sharp wide open at any aperture. At f/4, I would say it is as sharp as a zoom lens gets.

SSM is super quiet, close focus (and 1:4 magnification), no zoom creep (my only Sigma HSM is 18-250 which loves to zoom on its own), no CA issues. I also love the contrast and color out of the Sony (Sigma lenses seem to favor green a bit). The only advantage to Sigma might be that it gives you about 20mm more reach... nice to have but I would rather gain at the wider side. And price.

Needless to say, DT 16-50/2.8 SSM on a55 and E 35/1.8 OSS on NEX-6 are my go to options. For extra reach, I generally have Sigma 70/2.8 and usually Sony 135/2.8 STF at hand anyway to go on either camera.

I completely second EinsteinsGhost. Also went with the 16-50 2+ years ago, and I still enjoy it almost every day. It is sharp in the center wide open at every aperture on my A57. The only negative I could think of is the distortion at 16mm (which is easily corrected in camera (JPEG) and in LR (RAW) with a lens profile).

I would never trade the f2.8 for 50-70mm zoom range. In addition, one never knows whether the Sigma will work on the new SLT models coming out especially when OSPDAF is involved.

I have the new Sigma 17-70 "C" Its a great lens, especially for the cost.

I have also been researching the Sony 16-50 2.8 to see if it is an upgrade worth the money

Sigma:

Pros

Flat sharpness center to edge at all by wide angle

Sharpest at F5.6

70mm extra reach and long-end

Lower CA than Sony

Pretty Silent Focus (in quite locations automatic gain on they A77 mic pics up some clicking as it starts, stops or changes direction)

Price under $500

Looks really nice with monochrome design and is compact

Cons

F4 at 70 mm where it is a good portrait lens length BUT may not have narrow enough DOF for some types of portraits

Sharpest at F5.6

Drops out of F2.8 soon and is one stop slower by 70mm

Lens switch has to be changed for MF, no DMF no full time manual override adjustments like Screwmount with DMF or SSM

No weather sealing

Sony Lens JPG compensation does not support lens

Sony

Pros

Very sharp at F4 at all FL and pretty flat response (sharper than Sigma)

extra reach and wide end

F 2.8 available at all FL one stop more light at 50mm

Sharpest at F5.6

Less distortion at long end 50mm than sigma

Super Silent Focusing

Manual Focus Ring usable at all times for fine tuning

Weather Sealed like A77 body

Sony internal lens jpg compensation function supports lens

Cons

Can be soft and edge soft at F2.8 at all FL (but Sig doesn't even have option)

Sony bodies don't simulate DMF feature of turning on focus peaking like screw mount, should be simulated in AFS (Push since neither lens support 100% of DMF function)

More CA than Sony

Larger than Sigma

I used SLR GEAR tests to evaluate the lenses.. and my personal use of Sigma to confirm it is a nice lens.

For me optically they are close and I am not sure Sony is worth more. SSM and weather sealing have me thinking about it. If Sony simulated full DMF by turning on focus peaking after an AFS event.. so it behaved like a screw mount lens on DMF ... I would buy it for sure. Right now.. I am sticking with the Sigma because I own it and it would cost me about $250 to upgrade.

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K.E.H. >> Shooting between raindrops in WA<<Don't Panic!.. these are just opinions... go take some pictures..

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K.E.H. >> Shooting between raindrops in WA<<Don't Panic!.. these are just opinions... go take some pictures..

I went with the Sony 2+ years ago. And it is the only zoom lens I care about. It has been on the a55 practically all the time. I find the lens quite sharp wide open at any aperture. At f/4, I would say it is as sharp as a zoom lens gets.

SSM is super quiet, close focus (and 1:4 magnification), no zoom creep (my only Sigma HSM is 18-250 which loves to zoom on its own), no CA issues. I also love the contrast and color out of the Sony (Sigma lenses seem to favor green a bit). The only advantage to Sigma might be that it gives you about 20mm more reach... nice to have but I would rather gain at the wider side. And price.

Needless to say, DT 16-50/2.8 SSM on a55 and E 35/1.8 OSS on NEX-6 are my go to options. For extra reach, I generally have Sigma 70/2.8 and usually Sony 135/2.8 STF at hand anyway to go on either camera.

I completely second EinsteinsGhost. Also went with the 16-50 2+ years ago, and I still enjoy it almost every day. It is sharp in the center wide open at every aperture on my A57. The only negative I could think of is the distortion at 16mm (which is easily corrected in camera (JPEG) and in LR (RAW) with a lens profile).

I would never trade the f2.8 for 50-70mm zoom range. In addition, one never knows whether the Sigma will work on the new SLT models coming out especially when OSPDAF is involved.

The "C" model supports user updates and a dock for Sony is due out this spring.. Only a few older HSM lenses ever had a problem and were updated for free. SO while a consideration.. I am not too worried.

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K.E.H. >> Shooting between raindrops in WA<<Don't Panic!.. these are just opinions... go take some pictures..

I've gone back and forth a few times on my primary zoom so I figured I would chime in.

I started with the Sony 18-50 kit lens. I sold that and bought a Sigma 17-70 lens (prior to the "C"). I had that for a couple years and then went with the CZ 16-80. I loved the Zeiss. It was super sharp, the range was great too. But it was only about a year before I was itching for something new so I went to the Sony 28-75 f2.8. I figured I would like the constant aperture better since I shoot a lot indoors.

Well, I ended up missing the 16-28mm range a lot so I went to the Sony 16-50mm f2.8. I stuck with this lens for about a year. The aperture was nice and it was pretty sharp, I just was now missing the 50-75mm at the longer end. I could tell a difference in my pictures and I was just not able to get what I wanted with the 16-50.

So last December I bought the newer Sigma 17-70 "C" lens. I kept the Sony 16-50 for a few more weeks just in case but it is gone now. I love the Sigma, but of course I miss the constant 2.8 aperture. I listed the criteria I needed though to make my decision.

*I needed it for video so silent focusing was a must (both lenses do this excellent)

*With video, I use auto focus a lot, so the aperture is bumped up to f3.5. Due to that, the constant 2.8 is not a help on the Sony.

*I wanted the range of roughly 16-80 and the 17-70 fit great. The 16-50 left me missing the last 20mm.

*Decent macro was a bonus, so I sold my macro lens.

I still only slightly miss the 2.8 aperture. If I'm shooting indoors and it's dark, then I just use either my 30 or 50mm primes since they are f1.4. I also like to bounce flash. So for now I am currently using the Sigma 17-70 on my a77 and like it a lot. It's convenient, light weight, sharp.

Someone said it above, it mainly boils down to whether you want the constant 2.8 aperture or the 50-70mm at the long end. If you haven't made a decision yet, good luck!

I bought a SAL1650 when I was thinking of keeping my A580 and LOVED IT! I then got the itch and upgraded to an A77, I bought the combo A77 + SAL1650 because my gf said she wanted to keep the SAL1650 on the A580. This is my goto lens, I keep it on my a77 90% of the time with the other 10% being split between SAL35F18 and a few older minolta zooms.